Because of the emphasis now being placed upon child-resistant containers for dangerous substances such as drugs, household cleaners, poisons, and the like, many suggestions of combinations of containers and closures have been made in the past. Some of these combinations have utilized one-piece closures and special neck finishes on the containers so that the two have cooperating parts which render them child-resistant. Of the many types suggested, several have used axially depending or radially extending tabs on the margins of the closure which cooperate with abutments formed on the necks or the bodies of the containers adjacent the necks.
U.S. Pat. No. 3,770,153 to Gach et al. discloses a child-resistant closure of the "squeeze and turn" type in which the closure skirt has depending tabs and the container neck has abutments or recesses beyond which the tabs are positioned when the closure is turned fully on to the container. In order to remove the closure, it is necessary to squeeze the closure skirt along a diametric line normal to the diameter connecting the tabs to flex the skirt and the tabs outwardly so that the user can turn the closure in a retrograde direction and the tabs will pass the abutments which otherwise prevent removal of the closure.
In my earlier U.S. Pat. No. 3,989,152 and in Ostrowsky U.S. Pat. No. 3,993,208 the child-resistant combinations comprise tabs on the skirt of the closure and abutments on the container shoulder and they are so designed that the tabs pass on the inner sides of the abutments both when the closure is turned on to the container and when it is to be removed.
Experience has taught that it is preferable from a user's standpoint to provide for squeezing the closure skirt at the points and along the diameter actually connecting the tabs rather than along a diameter at 90.degree. from that connecting the tabs. Thus the manner of opening closures according to my earlier patent and the Ostrowsky patent disclosed above, may be more readily perceived and understood by users of sufficient age to be able to read the instruction legends which usually are molded into the top surfaces of such closures.
However, when the closure skirt has to be squeezed inwardly both when turning the closure onto and off of the container, repeated removals and replacements tend to give the plastic skirt a "set" in the inward direction thereby lessening its child resistance.
It is therefore, the principal object of the instant invention to provide a squeeze and turn child-resistant closure for use on and in combination with the threaded neck of a container which has one or more abutments on its shoulder near the neck but which provides that the locking tabs will pass on the radially outward side of the abutments when the closure is turned onto the container and which requires that these tabs be squeezed inwardly in order to remove the closure from the container.